مجله ترویج و توسعه آبخیزداری
پیاپی 22 (پاییز 1397)

Lack of rainfall in our country has doubled the importance of planning and optimal use of water resources. So that without the use of innovative methods and proper program in arid areas, the establishment of many plants is difficult or fundamentally impossible. On the other hand, rapid population growth, decreasing water resources and climatic changes, especially in arid and semi-arid regions of the world, has led to an investigation of strategies to increase agricultural production and rain garden along with optimal use of water. A significant portion of the Shirkouh lands in the city of Mehriz of Yazd province is used as dry gardens. Many of the fruit trees of the region, especially almonds, are dry farming, and rainy years produce a good crop. But in the warm and dry months of the year, they suffer from drought stress. Years of low rainfall and drought are water shortage problem. In this study, the effect of gravel filter on penetration optimization and its role in increasing the moisture storage of rain water harvesting systems using 72 plats and performing gravel filter treatment on half them were evaluated in a completely randomized design. The soil moisture was measured in 20 and 50 cm depths. According to the statistical analyzed data in 1390 year the gravel filter increased the soil moisture (p> 0.05). The 1391 year showed more significant (p> 0.01). Compared to the average soil moisture with gravel filter with control (natural-no pebble filter) have been increased 37%.

In order to achieve a sustainable development approach that guarantees the preservation and survival of watersheds, evaluation of the sustainability of watershed using watershed sustainability Indexes it seems necessary. The aim of this research was the evaluation of the sustainability of Beheshte Gomshodeh watershed Using watershed sustainability index (WSI) in the period of ten years (2006 to 2016). The UNESCO ? HELP demonstration was proposed an integrated watershed sustainability index (WSI), based on four criteria of hydrologic (quantity and quality), environmental, life, water policy issues and three parameters of pressure, state, response were used in order to achieve low, medium, and high levels of basin sustainability. The results showed that the pressure parameter with the score of 0.7812 and the response parameter with the score of 0.5312 had the highest and lowest scores for the assessment of the watershed sustainability.Also the results showed that the criteria of quantity hydrology with the score of 0.25 and the environment with the score of 1 are the most and least priorities for management.The value obtained for WSI was 0.6665, which represents an intermediate level of basin sustainability Which pays more attention to the region's sustainability level.

Nowadays, the status of water and soil resources is in a critical situation due to its excessive uses. Watershed management practices has been implemented in the field of natural resources to control and combat of these risks that are expected to provide the required performance for the expected time in the project. This research was done in Boodejan basin in Dehaghan of Esfahan province and its purpose was to assess the mechanical stability of structures were constructed at selected river basins. At first, field visits were conducted in the region and the structural characteristics and damages caused by them were registered and the relation between runoff and flood of basin were assessed with different returns period. Based on this evaluation, there were no degradation in two Lace-rock dams and scouring and the poor enforcement structures have been the demolition factors of structures in 39 stone and mortar dams with 34% and 17%, respectively. Due to the low lifetime of the structures, the signs of damage observed in them indicate the beginning of the destruction. If they are not repaired, they will face the problem in the future. In addition, the analysis the one of the topic structures showed that sliding, overturning and piping phenomena have not been observed based on maximum discharge and there was only possible the structural over stressing in the bed that may be due to its weight for over design.

Runoff management in developing urban areas and susceptible to flood, is a major concern in urban management. Runoff harvesting methods, can reduce the risk of flooding, furthermore, these methods are useful for non-potable purposes. Region 22 is one of the most important centers of population of Tehran that urban development is growing, rapidly. Impermeable surfaces increases and proximity this urban basin, with two catchment, Kan and Vrdyj, Has provided the conditions for floods. In this study, according to the specific topography of region 22, has been suggested the construction of earth dam for harvesting part of the basin runoff and use it for irrigation part of urban green spaces in this area. Finally, in order to justify this project, has been economic analysis in the previous (current situation) and after runoff harvesting (after construction of earth dam). According to the results, the best place for construction of earth dam, was detected in behind the hills of Chitgar park, Based on, Water Supply Requirementsfor irrigation of¬ Forest Park of Cheetgar, Khargoosh dare and Nation Garden of Herbology, that these are located near the proposed earth dam site, Volume of the proposed earth dam, was estimated, at about 9.775.000 Cubic meters. The runoff harvesting system, can provide Water Requirements 49.7% of the total area of ??green space in this area, also, it can control, flood peak flow, 100-yr or more in. Finally analysis of the benefits and costs indicated, cost in current condition is 1.55 time (4.011.892.840 Rial in year) more after runoff harvesting.

A critical look at the long-term vision and strategic plan of the Ministry of Energy suggests that a change in thinking from a traditional mechanical approach to a systemic one is being conceived. However, the essential features and components of an ecosystem-based approach need to be clearly delineated. Also, objectives and priorities should be defined and a hierarchical multi-scale river basin planning system should be developed. Lack of an integrated indicator-based plan for the management of river basins and watersheds is one of the main reasons for the limited success in water resources management in Iran. Absence of a coherent and systematic conceptual framework for watershed assessment and management is another significant shortcoming. Through a comparative analysis, this paper introduces the watershed governance approach as a substitute for water governance. The former concept is fully in line with ecosystem-based and nature-based solutions and can be considered as a paradigm shift in water resources management.

Among the major challenges facing agriculture and water resources, one can mention the phenomenon of climate change and its impacts. The Global Criculation Models (GCMs) can provide the best information about the response to increasing the concentration of greenhouse gases. Since the output of these models does not have sufficient spatial and temporal accuracy to study the effects of climate change on hydrological systems, it is necessary to provide output data for small-scale general turning models. In this study, the SDSM statistical magnitudes and for the climate change assessment, the CanESM2 model reported in the IPCC's based on three scenarios RCP2.6, RCP4.5 and RCP8.5 is used. The daily minimum temperature and maximum temperature of the land synoptic station is Fars province, and the temperature is predicted for the three periods 2040-2011 (2020S), 2070-2070 (2050S) and 2099-2071 (2080S). The results of the research showed that the SDSM model is well advanced to minimize and maximize temperature, and is a suitable model for exponential smoothness of climate parameters of temperature for the Lar synoptic station. According to the results of the CanESM2 model, in both three scenarios (RCP2.6, RCP4.5, RCP8.5) and all three periods (2020S, 2050S, 2080S), the minimum and maximum temperature has been increased, so that the increase for the minimum temperature and the maximum period (2020S) was between 1.12 to 1.29 and 2.01 to 2.30 celsius degrees, and the increase for the minimum and maximum temperature (2050S) was between 1.47 to 2.35 and 2.61 to 4.14 celsius degrees and the temperature rise (2080S) relative to the base period for minimum and maximum temperatures is between 1.46 to 3.13 and 2.7 to 5.94 celsius degrees.

Climate change and recent drought combined with the high use of groundwater resources by the agricultural sector, has led to a major water crisis in Iran. In this conditioin, farmers should use optimal water management techniques. Effective planning and action in this field requires better understanding of the factors affecting farmer's behavior. In the present study, using a descriptive-correlation method, this issue was investigated among the fruit farmers. The statistical population of the study was all the fruit farmers in Maragheh Township (11742 people). According to the Cochran sampling formula and using randomized multistage sampling method, 228 of the fruit farmers were selected and studied. The majority of apple gardens in Maragheh, are located in the Urmia lake basin, and the fruit farmers of this Township, produce an important part of the apple of the province and the country. The tool used to collect data was a questionnaire whose content validity was confirmed by experts in this field. A preliminary study was carried out on 30 fruit farmers and Cronbach's alpha of 0.85 was obtained. The results of this study showed that the majority of fruit farmers (97.7%) used the optimal water resources management methods at moderate level. Multiple regression analysis showed that variables such as level of educational needs, amount of water consumed, age, amount of information received from mass media, total area of ??the garden and fruit farmers 's perception of reducing water resources explained 30% of changes in the level of use of optimal water resources management methods.